864 research outputs found
Review of \u3cem\u3eThe Career and Writings of Demetrius Kydones: A study of Fourteenth-Century Byzantine Politics, Religion and Society\u3c/em\u3e
Assessing the Real-Time Informational Content of Macroeconomic Data Releases for Now-/Forecasting GDP: Evidence for Switzerland
This study utilizes the dynamic factor model of Giannone et al. (2008) in order to make now-/forecasts of GDP quarter-on-quarter growth rates in Switzerland. It also assesses the informational content of macroeconomic data releases for forecasting of the Swiss GDP. We find that the factor model offers a substantial improvement in forecast accuracy of GDP growth rates compared to a benchmark naive constant-growth model at all forecast horizons and at all data vintages. The largest forecast accuracy is achieved when GDP nowcasts for an actual quarter are made about three months ahead of the official data release. We also document that both business tendency surveys as well as stock market indices possess the largest informational content for GDP forecasting although their ranking depends on the underlying transformation of monthly indicators from which the common factors are extracted.Business tendency surveys, Forecasting, Nowcasting, Real-time data, Dynamic factor model
Single channel study of the spasmodic mutation α1A52S in recombinant rat glycine receptors
Inherited defects in glycine receptors lead to hyperekplexia, or startle disease. A mutant mouse, spasmodic, that has a startle phenotype, has a point mutation (A52S) in the glycine receptor α1 subunit. This mutation reduces the sensitivity of the receptor to glycine, but the mechanism by which this occurs is not known. We investigated the properties of A52S recombinant receptors by cell-attached patch clamp recording of single-channel currents elicited by 30 – 10000 μM glycine. We used heteromeric receptors, which resemble those found at adult inhibitory synapses. Activation mechanisms were fitted directly to single channel data using the HJCFIT method, which includes an exact correction for missed events. In common with wildtype receptors, only mechanisms with three binding sites and extra shut states could describe the observations. The most physically plausible of these, the ‘flip’ mechanism, suggests that pre-opening isomerisation to the flipped conformation that follows binding is less favoured in mutant than in wild-type receptors, and, especially, that the flipped conformation has a 100-fold lower affinity for glycine than in wildtype receptors. In contrast, the efficacy of the gating reaction was similar to that of wild-type heteromeric receptors. The reduction in affinity for the flipped conformation accounts for the reduction in apparent cooperativity seen in the mutant receptor (without having to postulate interaction between the binding sites) and it accounts for the increased EC50 for responses to glycine that is seen in mutant receptors. This mechanism also predicts accurately the faster decay of synaptic currents that is observed in spasmodic mice
Superactivation of AMPA receptors by auxiliary proteins
Glutamate receptors form complexes in the brain with auxiliary proteins, which
control their activity during fast synaptic transmission through a seemingly
bewildering array of effects. Here we devise a way to isolate the activation
of complexes using polyamines, which enables us to show that transmembrane
AMPA receptor regulatory proteins (TARPs) exert their effects principally on
the channel opening reaction. A thermodynamic argument suggests that because
TARPs promote channel opening, receptor activation promotes AMPAR-TARP
complexes into a superactive state with high open probability. A simple model
based on this idea predicts all known effects of TARPs on AMPA receptor
function. This model also predicts unexpected phenomena including massive
potentiation in the absence of desensitization and supramaximal recovery that
we subsequently detected in electrophysiological recordings. This transient
positive feedback mechanism has implications for information processing in the
brain, because it should allow activity-dependent facilitation of excitatory
synaptic transmission through a postsynaptic mechanism
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Building confident ways of working together around higher-risk birth choices
Women who want to make choices about their births which are different from standard care practices or fall outside guidelines, especially when their pregnancies are categorized as 'higher risk', may often feel that midwives are more aligned with the hospital system which employs them than with the women who receive their care (Kirkham 2010). Midwives who seek to support women and provide a care pathway which is tailored to the woman's unique circumstances, often find themselves bullied and reprimanded and their practice subjected to intense scrutiny (RCM 1996, Gillen et al 2008). A risk-averse hospital culture, where standardized pathways aimed at risk reduction are the driving factors behind guidelines and protocols, provides a conflicted environment for the midwife aiming to deliver authentically woman-centered care which bears any resemblances to the government policy rhetoric of informed choice as set out in documents such as Maternity matters (DH 2007)
Book Review of \u3cem\u3eMaximus the Confessor. Jesus Christ and the transfiguration of the world\u3c/em\u3e, By Paul M. Blowers
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